Gas valve



C. M. GARNER June 3, 1952 GAS VALVE 5 Sheets-Sheet 1 Filed June 19, 1946 m 33 m n N w W T MM U A W M. 3 v

J1me 1952 c. M. GARNER 2,598,902

GAS VALVE Filed June 19, 1946 5 Sheets-Sheet 3 We CH? DE M. GARNER BVJW r 2,11.

June 3, 1952 Filed June 19, 1946 C. M. GARNER GAS VALVE 5 Sheets-Sheet 4 IQTTOEA/EKS.

June 3, 1952 c. M. GARNER 2,598,902

' GAS VALVE Filed June 19, 1946 5 Sheets-Sheet 5 Patented June 3, 1952 GAS VALVE Claude M. Garner, Clayton, Mo., assignor, b y mesne assignments, to Missouri Automatic Control Corporation, a corporation of Missouri Application June 19, 1946, Serial No. 677,830

10 Claims. 1

The present invention relates to a gas valve. More particularly, it relates to a valve of the diaphragm type, wherein the diaphragm is controlled by certain control devices that respond to the peculiar changes in physical conditions that are critical.

Broadly, it is an object of the invention to provide a gas valve of this type that is caused to respond to changes in space temperatures, with a limit switch override thereon, the space temperature control device and the limit switch device each comprising a single valve device of simple construction and operation. More particularly, it is an object to provide a valve, as above set forth, wherein there is a diaphragm chamber and gas passages controlling the gas flow to and from said chamber, together with a first valve operable into either of two positions, wherein it controls Whether said passage shall be connected to a source of gas supply or to exhaust, together with a second limit switch valve, also to control said passage and to determine whether it be connected to a source of gas supply or exhaust, regardless of the determination by the first valve.

A further object of the invention is to provide a valve, as in the foregoing paragraph, wherein each of the control devices operates with an instantaneous or snap action between twd opposed valve seats.

A further object of the invention is to provide a novel manual means to cause the gas valve to open, even in the absence of power. A further object is to provide a manual means, as aforesaid, which automaticallyreturns the valve to its automatic control as soon as power is restored.

A further object is to provide a valve of the diaphragm type and to provide controls therefor which are relatively simple in construction, easy to fabricate and durable.

Other objects will appear in the description to follow.

In the drawings: i

Fig. 1 is a plan View of the valve with the cover partly broken away and in section;

Fig. 2 is an end elevation, taken from the left end of Fig. 1;

Fig. 3 is an end elevation, taken from the right end of Fig. 1, with the hood or cover shown in section;

Fig. 4 is a lengthwise vertical section, taken on the line 4-4 of Fig. 1;

Fig. 5 is a vertical transverse section, taken on the line 5-5 on the left end of Fig. 1;

Fig. 6 is a longitudinal vertical section, taken 2 on the line 66 in the upper left middle of Fig. 1;

Fig. 7 is a section, taken on the line l'l in the lower left middle of Fig. 1;

Fig. 8 is a side elevation of the valve with the cover shown in diametrical section;

Fig. 9 is a side elevation of the valve, taken from the side opposite that of Fig. 8 and with the casing shown in diametrical section;

Fig. 10 is a section on the line Ill-40 of Fig. 8, showing the left hand end of the limit switch mechanism;

Fig. 11 is a vertical section on the line ll--Il of Fig. 8, showing additional parts of the limit switch mechanism;

Fig. 12 is a horizontal section on the line l2-l 2 of Fig. 8, showing part of the limit switch mechanism;

Fig. 13 is a top view of a valve housing castm Fig. 14 is a vertical section on the line I4-I4 of Fig. 13;

Fig. 15 is a bottom view of the casting of Fig. 13;

Fig. 16 is an enlarged diametrical section through the connection into the bellows for the limit switch mechanism;

Fig. 17 is a side elevation of an operating lever of the limit switch mechanism;

Fig. 18 is a view of the room thermostat shunting switch in closed position, this switch being shown in open position in Fig. 6;

Fig. 19 is an enlarged view of the manual operating mechanism shown in Fig. 9;

Fig. 20 is an end view of this part of Fig. 9, taken from the right end thereof;

Fig. 21 is a view of an operating crank in this mechanism; and

Fig. 22 is a wiring diagram of the mechanism.

The valve includes a main lower body portion 10 having an inlet II and an outlet [2, the outlet opening into a vertically disposed circular wall [3 that provides a circular valve seat [4 at its upper end. This valve seat constitutes a port of communication from the inlet H to the outlet l2. The inlet opens into a lower diaphragm chamber l5 formed as an extension of the casting H1 at its upper surface and being circular.

the diaphragm margin resting upon the rim I6. The cap is screwed to the lower casting l9 by suitable screws 29. It will be observed that this cap is formed with a depending flange 2| and a platform 22 that afford an upper diaphragm chamber 23. The diaphragm H has centrally disposed valve and weighting elements [9 and 24, respectively, secured to it, the valve element l9 cooperating with the valve seat 14. p

The operation of the diaphragm follows one of the conventional arrangements in that, when the pressure from the inlet side that acts belowthe diaphragm is also admitted to the diaphragm chamber 23 above the diaphragm, the valve l9 will be closed by the action of gravity, but, when inlet line pressure in the upper diaphragm chamber 23 is exhausted to atmosphere, then the somewhat higher line pressure, acting on the lower side of the diaphragm, will raise the same and open the valve l9.

The control for the valve I9 is here two-fold. The lower valve housing It] has a passage 25 therein that communicates with a. passage 26 in the cap !8. This passage 26, in turn, registers with twcbranch passages 21 and 28 in a. valve housing castin 29 that is attached to the upper surface of the platform 22-. This casting 29 (see Figs. '13'-15) has two upstanding cylindrical portions 39 and 3! forming valve housings, into the bottom of which the passages 21 and 28 open, respectively;

Referring first to the valve housing 39 (Fig. 5), within this housing is a lower valve seat member '33 having av lower circular flange with a threaded upstanding boss 34' rising from the central; portion thereof. A circular group of ports 35" through the flange of the member 34 are provided and arranged to register with a port 36 leading through the bottom of the cylindrical member 39, which port, in turn, is adapted to register with a port 31 that extends through the cap member I8 into the diaphragm chamber 23 above the diaphragm. The port 36' in the member 29 opens into an annular groove 38, so that there will be a distribution of gas flow between all of the openings 35. and the passage 35. Immediately above the ports 35', the boss 34 has a groove 39 into which the ports 35 communicate.

There is a central opening 49 through the boss 34 which registers, with the upstanding part of the passage 21. It thus receives line pressure gas. A suitably perforated pliable washer is interposed between the flange of the member 33 and the bottom of the cylindrical housing 39. The opening 40 has a ball valve seat 4 1 formed at its upper end, with which a ball valve 42 may register. A coil spring 44 urges the ballvalve upwardly away from its seat.

The valve housing 30 also receives an upper valve seat member 41, which valve seat member has; aninternally threaded cavity 46 in its lower end, which receives the threaded boss 34; of the lower valve seat member 33. There is a vertical groove 48 extending up one side of the boss 34, so: that there is always full communicationbee tween the upper part of the cavity 46 and the upper; diaphragm chamber 23. The upper valve seat member 4;! has a bore 49 that iscoaxial with the: cavity 46. This bore 49 provides an upper valve seat 59 for the ball valve 42 opposite the valve seat 4|. There is a transverse opening 51 leading from the bore 49 to a peripheral groove 52 on the valve seat member 41. This roove- 52 registers with a port 53 leading downwardly at an angle into communication with. a

groove 54 in the lower surface of the casting 29, which groove cooperates with the top of the cap member IE to form a passageway. This passageway leads into the interior of the other cylindrical valve housing (H. To this end, it registers with a circular groove 55 in the bottom wall of the cavity of the cylindrica1 housing 3|.

There is a lower valve seat member 56 in the cylindrical member 3| that is similar to the valve seat member 33 in the cylindrical member 39. It has an upstanding central portion 5! and a flanged bottom. The flanged bottom portion engages against a suitably ported sealing washer, and has a plurality of openings 58 arranged circularly about its center and adapted to register with the groove 55 to permit gas flow from the groove to the top part of the valve member 56. The valve member also has a groove 59 to permit the gas to flow from its bottom to the top.

The valve member has a central opening 69 with a valve seat 61 at the top thereof, this valve seat being adapted to receive aball valve 62. The upstanding portion 51- of this member has a pe ripheral' groove 63 'at' its base to insure fluid flow from the groove 55- to the cut-away notch 59.

The valve seat member 56 is supported within an upper valve seat member 64 that is threaded into-the cylindrical member and has a threaded cavity 65, into-which the valve member fits. This cavity has an upper valve seat 66 with which the ball valve 62 may register; Above the valve seat 66, there is a bore Bl, from which a passage 68 extends to a peripheral groove 69 around the outside of the plug 63. This groove 69 is adapted to register with an outlet opening in formed in a lateral extension 101 of the cylindrical member 9 I. This opening 19 may receive a pipe fitting to conduct the gas to any suitable place.

The two operating means for the pilot valves 42 and 62 will now be described.

The valve 42 is operated. by a magnetic coil that is adapted to be connected for operation when a room thermostat or the like closes. This part of the mechanism includes a bracket H. This bracket or. base is in the general shape of an inverted U, with horizontally projecting ears that are screwed to upstanding bosses on the member lt.

The bracket ll receives on its upper surface. a U-shaped coil support 12. A center postv 13 is permanently fixed to the support 12, and, about this post, there is provided a magnetic coil 14.

The inner vertical arm of the bracket 12 has two upstanding ears l5. and 16 over which is fitted a rocking armature 11. The armature has a tongue portion 18: that projects outwardly through the two upstanding ears or prongs 15 and 76. This tongue extends laterally. as shown in Fig. 1, to the back sides of the two prongs l5 and 16. Thus, the armature is restricted against movement to the leftward in Figs. 1 and 6;. It is restricted against movement to the right by the presence of a plate 99 that is held by screws 8| to its top. This plate is provided with two downturned hooks 82 that are located adjacent the left hand faces of the two prongs 15 and 16. They, therefore, prevent the armature plate 11 from slipping to the right in Figs. 1 and e;

The same inner upstanding arm of the bracket 12 receives a fitting 83 that has an outstanding end 84 at its lower part and an overhanging hooklike portion 85 at its top. This hook-like portion passes through an opening in the, armature l1 and, by overlying the armature, limits the upto the coil support 12 and operating in a vertipending prongs I25.

Ward displacement of the right end thereof, as shown in Fig. 6.

A coil spring81 is stretched between the projecting end 18 of the armature member and the lower projection 84 on the piece 83. It, therefore, urges the armature member 11 to pivot in a clockwise direction, as appears in Fig. 6, the rocking taking place about the edge of the upstanding arm of the bracket 12 between the two prongs 15 and 16.

When the coil 14 is energized, it is adapted to attract the armature 11 and rock its outer end downwardly, stretching the spring 81. The outer or forward end of the armature carries an adjustable abutment screw 90, for a purpose to appear.

An actuating blade 92, preferably of spring-like material, is formed from a plate with a large opening 93 therein. This plate has backwardly projecting ears 94 and 95 that are set back to rest on the projecting portions of the plate 83 that extend, as shown in Fig. 3, laterally beyond the limits of the upstanding arm of the bracket 12.

The arm 92 has a forward extension 91 thereon that is preferably ofiset downwardly, as shown. This arm engages on a push rod 98 that extends down through the plug 41, so as to impinge upon the ball valve 42. A suitable diaphragm 99 is provided to seal off the top of the cylindrical member 30, and yet to permit reciprocable operation of the push rod 98.

Below the bracket H, a switch mechanism is fastened. This switch consists of two spring blades I and IOI that are secured to the bottom of the supporting bracket H by suitable screws I02, with the interposition of the necessary insulation. As shown in full lines in Fig. 6, the two switch blades I00 and IOI normally rest with their contacts I03 and I04, respectively, disengaged.

This switch is part of a manual operating mechanism which is designed to depress the ball valve 42 and to close the switch contacts at the same time. This manual mechanism includes an upstanding support standard H0 that is riveted to the outer vertical side of the inverted U-shaped support 1|. The standard H0 slidably supports a manual operating strip II I, which strip has a vertical slot I I2 therein that receives a rivet I I3, which rivet is fixed into the standard H0. The standard likewise has a projecting nib H4 that fits within the slot so as to prevent rotation of the manual strip III and to confine it to vertical movements.

In addition to the slot H2, the strip III has a slot H5 at its bottom that extends transversely thereof. On its side edge, the strip III has a projecting shoulder H6 that is disposed so as to come under an arm H1 that projects at an angle from the rocking armature 11.

On the outer leg of the coil supporting bracket 12, there is a flanged plate I20. The flanges confine this plate to vertical movement, and it is further confined by a headed rivet I2I secured cal slot I22 in the flanged plate I20.

This plate, at its upper end, has a curved neck portion I23 that passes upwardly through an opening in the actuating blade 92 and is hooked over the top thereof.

The lower end of the plate I20 has two de- These prongs receive a notched piece of insulation I26 that overlies the upper switch blade IOI. The notches and their engagement with the prongs I25 prevent this across the terminals I39 and I42.

strip of insulating material from slipping out of position. It is further confined by an ine wardly turned prong I30 that overlies it. This prong I30 extends above the switch blades and between the vertical sides of the bracket 1I. It also underlies a semi-circular crank I 32. This crank is supported in the side walls of the su porting bracket II and passes through one of the side walls, to provide a curvedcrankarm I33. Between the'two side walls of the bracket 1!, the crank I32 has an offset semi-circular portion I35. When the crank is turned, this offset portion may move from its position in Fig. 6 to its position in Fig. 18. In Fig. 6, it will be seen that it presents its flat part to the inwardly turned tongue I30, but, when it is turned to slightly beyond 90", it depresses the prong I 30 and closes the two switch contacts.

This crank is actuated by the engagement of its semi-circular arm I33 in the slot I I5 of the manually operating strip III.

It will be seen that, when the manually operating strip is pulled upwardly, it turns the crank arm slightly over 90. In so doing, it closes the switch contacts and also causes the tongue I30 of the plate I20 to move downwardly. This latter movement causes the hooked upper part I23 on the plate I20 to engage the operating plate 92 and bring the same downwardly toseat the valve 42 on its lower seat.

Fig. 22 shows the manner of electrically connecting this part of the mechanism. In Fig. 22, a source of power is shown in the form of a secondary winding I31, it being connected to two terminals I38 and I39. A wire I40 connects the terminal I30 with the coil 14. A wire I4I connects the other end of the coil 14 with a terminal I42. This terminal is connected by a wire I43 to the room thermostat, generally indicated at I44. The other side of the room thermostat is connected by a line I45 with a terminal I46, that is connected by a line I 41 with the terminal I39.

The switch contacts I03 and I04 are connected The switch contact I03 is connected by a line I with the terminal I39, and the switch contact I03 is connected-by a line I 5| with the terminal I42.

The limit switch mechanism is supported upon the cap I8 beside the coil 14. To this end, there is a supporting plate I attached to the top of the cap I8. A frame I6I in the form of an inverted U is mounted over the top of the plate I60.

The plate I60 supports a tubular head I62 which has a threaded end I63 adapted to pass through the plate I60 and to be secured thereto by a nut I64. This head I62 receives the end of a tube I65 that is connected to a bulb I66. This bulb I66 will be located at a point that reflects critical temperatures.

The head I62 receives one end of a bellows I61.

The other end of this bellows is connected to a head I68 of a reciprocatable member I69, this member having a depending guide pin I10 at its lower end, which is adapted to fit loosely in a bore I1I in the head I62, thereby to restrain lateral movement or buckling of the non-rigid bellows. The bellows I61 is in communication with the tube I65, via that annular space between the loose fitting element I10 and the wall of the bore I1I, so that it will receive the expanding fluid from the bulb.

The reciprocatable or expansible member I69, at its upper end, receives a threaded actuating stud I 13, having a flange I14 thereon. It will be seen that the stud I13 is threaded into the member I69 and has a kerf at its outer end, so that the positionof the-flange I'14t, relative to the upper end of the bellows I61, may be varied. Means for indicating the relative positions of the upper. end of the bellows I61 and thefiange I1.4;is provided, and comprises a gear I16 rigidly attached to the upper end of the stud I13 and a larger meshing gear I11 pivoted on the top of the inverted U-bracket IBI. The upper surface of thegear H1 is graduated (Fig. 1)., and these graduations register with a pointer I18 formed in the edge: of an opening I19 stamped into the top of the U-shapedbracket I6I The flange I14, on the actuating member I13, is adaptedto be engaged by depressed portions on a primary lever I80 mounted for rocking on a spindle I8 I fastened in the supporting bracket I-6-I. The primary lever I88 has a depending rearward extension I82 that receives one end of each of apa-ir of coil springs I83, that constitute toggle springs. The other end ofeachof these coil springs is attached to a vertical portion I85 of a secondary lever" I86. 7

This secondary lever I86 constitutes a valve actuating lever. It is of the shape shown in Fig. 1'1- itsbaok portion being generally channelshapedwith outstanding knife-edged bearings I88 at its inner end. These knife-edged bearings are adapted to fit into relatively large openings I89 in the two side portions of the bracket I6 I'. These openings I89 have angular crotches into which theknife-edged bearings I88 fit for rocking movement. It will be seen that the coil springs I83 urge the knife-edged bearings into engagement withthe crotches.

The forward end of the valve actuating lever IBB' has-the vertical portion I85 thereon, as already mentioned; From this portion I85, an actuating end- I98 projects. This-end I90 has a forked outer end which straddles the threaded upper end" of a valve rod or'stem I9I. This rod passes down through asuitable opening in the valve seat member 64, and has the valve 62 integral with the bottom thereof. The valve rod I9I receives a nut I92 above the forked end I90 of the secondary lever I86, which nut is adjustable thereon. The rod- I9I' passes through a flexible diaphragm I93, that is sealed across the recessed top of the val-veseat member 64'. The rod I9I isclamped to the diaphragmbya-- suitable removable washer and nut arrangement I95.

The actuating mechanism for the valve 62 thus includes the bellows I6 1, the stud I13 and its flange I14, the primary lever I89, the secondary lever I86, the nuts I92 and I95, and thestem or red I9-I', together w-ith the springs I83; This constitutes an over-center snap-action mechanism, with the modification that the springs I83 exert a constant clockwise force upon the primary lever I80, as well as reversing forces on the secondary lever I85. The temperatures of raising and lowering the valve 62- are adjustable; The operation will beset forth hereafter.

Operation Thenormal operationoi this valve consists of'a cycling under the influence of the room thermostat.

Assume, at the start, that the room thermostat is satisfied, which means; that the main diaphragm valve I9 should be closed against the seat I4. This will come about when. the gas pressure conditions above. and below the diapresent in the lower diaphragm chamber, exerting an opening influence on the diaphragm, there must also be a gas pressure above the diaphragm in the upper diaphragm chamber 23, in order'to counteract that below the diaphragm.

The inlet gas line pressure can pass from the lower diaphragm. chamber through the passages 25: and. 2.6: to the port passages 21 and 28: that lead to the valvesv 42 and 62, respectively. At the start, the valve 42 will be in its upper position against the seat 50. The valve 62 will be. in its lower position against the seat 6!. As a consequence, the gas line pressure through the passage 28will enter the lower chamber 59 and will there be checked, becauseof the closed valve 62'. However, the gas from the passage 21 will flow upwardly into. the chamber 40 and thence will flow around the valve 42. It is prevented from going to the upper chamber 49 by the valve, but can flow into the chamber 46,,and thence, by the cut-away passage 48, downwardly to the groove 39, the circular series of openings 35 and into the circular groove 38, whence it may pass through the passages 36 and 31 to the upper side of the diaphragm, thus equalizing the pressures on both sides of the diaphragm and permitting the valve I9 to close.

It will be seen that the failure Of line pressure for'one reason or-another will not affect this situation because the pressure is the same when the valves 42 and 6-2 are in the position shown, regardless of what the line pressure is.

If the room thermostat I44 closes, it brings power to the coil 14, as is evident from Fig. 2 2, the circuit being completed from the coil r31 through the terminal I38, the line I49, the coil 14, the line I4I, the terminal I42, the line I43, the-thermostat I44, the line I45, the terminal I46, the line I41, and the terminal I39 back to the secondary coil I31. When the coil 14- is thus energized, it draws down the rocking armature 11 until the same engages the top of the post 13. This downward movement of the armature 1'! causes the screw to engage the spring actuating blade 92, forcing the same down. It rocks by the engagement of its inner end in the notches on the sides of the upstanding end of the bracket 12 so that its outer end 91- depresses the pin 98 and displaces the ball Valve 42 from the seat 50' to its lower seat 41. This action is, opposed by the coil spring 44 of the valve. Also, the rocking of the armature 11 downwardly causes extension of the coil spring 81', which tends to return the armature when the magnetic force is relieved.

When the ball valve 42 moves downwardly, it closes off the input of'line gas from the passage 21 to the chamber 46, which chamber is in direct and open communication with the upper diaphragm chamber 23. Thus, the line pressure an no longer reach the upper diaphragm chamber. Also, this upper diaphragm chamber is then connectedto exhaust. The valve chamber 48, now closed to'line pressure, is open to the passage 49 which communicates through the passages 5t, 52, 53 and 54 to the other cylindrical member. At this other cylindrical member, the passage- 54 registers with the annular groove 55 which is in communication with the circular series of passages' 58 that lead into the upper valve chamber 65' through the notch 59. This valve chamber 65 is open past the valve seat 86, and the passage 61 to the passage 68, which is in communication with the peripheral groove 69.. that registers with the exhaust outlet 10. This. means that. what gas was. in the upper diaphragm chamber 23 9 passes therefrom to the upper side of the valve 42, thence around to the upper side of the valve 62 and out to exhaust, relieving the pressure in the upper diaphragm chamber to atmosphere. However, the lower diaphragm chamber is still subjected to line pressure so that the diaphragm is caused to lift and to admit gas past the main valve seat l4 to the outlet l2.

This condition would normally continue until the room thermostat is satisfied, reopening and relieving the magnetic coil 84, so that ultimately the valve 42 returns tothe position shown in Fig.5.

It may happen, however, that the temperature at the chosen critical point, such as in the furnace bonnet, exceeds the value for which the limit mechanism is set. Thereupon, the limit valve will be shifted, and the main valve closed regardless of the room thermostat and the valve 42.

The limit valve 62, during normal operation, when th temperatures at the bulb I66 are below the critical value, will be in its lower position. Under such circumstances, the bellows I61 will be contracted, and the stud I13 and its flange I14 will be in a downward position. The force of the springs I83 is constantly eccentric and clockwise (Fig. 7) on the primary lever I80, so that it rocks against the flange I14. Its right end (Fig. 7) and its axis of force upon thesecondary lever I86 will be below the knife edges I88, so that its force acts counterclockwise upon the secondary lever I86, and holds the end I90 thereof downward against the nut I95, that, in turn, holds the valve 62 down against its lower seat 6 I.

When expansion of the bellows I61 elevates the flange I14, the primary lever I 80 rocks its outer end I82 upward, and displaces the right end of the force axis of the springs I83. The force on the secondary lever will remain counterclockwise until the force axis of the springs is moved across to above the knife edges I88, whereupon the secondary lever will rapidly move clockwise, its speed increasing with degree of upward movement of its left end (Fig. '1). It will cause its end I90 to engage the nut I92, to shift the valve 62 to the seat 66, with a snap action. Thereafter, overtravel of the primary lever I89 causes no further movement of the secondary lever, but merely moves the right end of the springs upwardly. The maximum of such movement is always less than enough to remove all counterclockwise leverage of the springs upon the primary lever.

As will appear, shifting of the limit valve 62 will cause closing of the main valve, and hence cooling of the furnace. When the bulb I66 cools, the bellows I61 will contract, lowering the stud I13 and its flange I14. The constant clockwise force (Fig. 7) of the springs I83 upon the primary lever I80 will cause it to follow the flange I14 by rocking clockwise. After any overtravel is absorbed, the downward movement of the right end of the primary lever will begin its over-center function. The left end of the springs I83, at the portion I85 of the secondary lever, will be positioned by the nut I92. When the descent of the right end of these springs crosses their force line over to below the knife edges I88, the secondary lever will quickly rock'counterclockwise, its end I96 shifting to the nut I95, and causing the valve 62 to be returned to its seat 6| with accelerating speed.

The temperature value at which the valve 62 is elevated is a function of the adjustment of the stud I13, since the lower position of thenut I85 on the valve-stem is fixed. The position of elevating the valve is constant so far as the relative positions of the primary lever, the secondary lever, and the springs are concerned.

The temperature at which the valve 62 is-lowered is a function of the adjustment of the upper valve stem nut I92. When the valve is raised, the nut I92 fixes the left end of the force line of the springs I83, which is that point adjustably fixed by the selected positioning of the nut I92. Hence, to move the force line across the knife edges I88,- the right end of the primary lever I must move. the right end of the springs I83 more or less, as is determined by the aforesaid selection of the position of the nut I92. The more the movement of the primary lever, the greater the differential between the temperature at which the limit mechanism causes closing of the main valve I9, and the temperature at which it permits reopening thereof.

The limit mechanism may ordinarily be expected to operate when the room thermostat is closed demanding heat. As a result, the valve 62 is ordinarily lifted when the valve 42 is in its lower position. It will be remembered that, when the valve 42 is in its lower position, the line pressure is cut off from the upper diaphragm chamber 23, and that chamber is open to atmosphere. However, when the valve 62 is elevated, this situation is changed. The previous exhaust line went from the passages 31, 36, 35, 48, the valve cham ber 46, thence over the top of the valve 42, the passage 49, the passages 5|, 52, 53, 54 to the other valve, by way of the passages 55, 58 and 59, and thence over the valve 62, which was in the position shown in Fig. 5, and ultimately to atmosphere. However, when the valve 62 is elevated, the exhaust passage is cut off at the valve seat 66, so that the upper diaphragm chamber 23 no longer can exhaust. Furthermore, the elevating of the valve 62 from the valve seat 6| admits gas from the passages 25, 26, 28 and 60, around the valve 62, back through the passages 59, 58, 55, 54, 53, 52, 5 I, 49, around the valve seat 50, because the valve 42 is depressed, and thence back into the upper diaphragm chamber 23. Thus, despite the fact that the room thermostat is demanding heat and the valve 42 is lowered, line pressure is admitted to the upper diaphragm chamber, the pressure conditions equalized above and below the diaphragm, and the main valve closes.

It will also be seen that the particular position of the valve 42 has no effect on the ability of the valve 62 to dominate, because, if the valve 42 should be released to its upper position, it would merely mean that the exhaust line would be cut off at two points and the line pressure admitted from two sources into the upper diaphragm chamber. This results because the exhaust passages always are under control of the valve 62, regardless of which position the valve 42 may assume.

The present mechanism provides means to open the valve manually in case of power failure, coupled with mechanism to return the valve automatically to control by power upon restoration thereof. Such operation is here attained by the manual blade I I I, which may be lifted.

Lifting of the blade III rocks the curved end I33 of the crank I32, and the semi-cylindrical portion I35, and thereby depresses the tongue I30 of the end plate I28. The contact of the tongue I30 with the insulating sheet I26 and I the contact of the latter with the switch blade tact I02,-as shown in Fig. 18, thus closing the switch. Likewise, the downward movement of the end plate I28 causes its upper hook I23 to engage theoperating member 92 and to :depress the same, :drawing it away from the rocking armature l'l,andcausing'the end '9! of the member 92to depress the pin-SB to move the valve 42 from-the valve seat to the valve seat '4 I. When this movement of the blade I I I is completed, the crank arm I will have moved slightly beyond 90, so that the upward force of the spring-like switch blades willmerely tend to drive the crank arm further, rather than to reverse it. Such further movement-is prohibited by the engagementof the 'crank parts. Hence, the parts will stay in the positions aforesaid, by this overcenter lock arrangement.

As the strip II I is moved to its upper position, its shoulder II6 rests immediately under the projection 'I I! on the armature I! when the I center, until the spring action of the blade .co-

operates with gravity and the downward pull of the armature T! to complete the release .of the Y manual means and the opening of the switch. Thereupon the further operation will "return to controlthe room thermostat.

What is claimed is:'

1. In a gas valve, a main housing having an inlet and an outlet, and a valve seat between them, a valve member cooperable with the valve s'eat a diaphragm for operating the valve, said diaphragm extending across the housing to provide a =first diaphragm chamber, a cap member adapted to fit over the housing and havingedges to clampthe'diaphragm to the housing, and providing -a second diaphragm chamber, a valve housing member having two valve chambers therein, avalve in each valve chamber, a con trol passage from one diaphragm chamber to the firstvalve-chamber, an exhaust'passageand a pressure "passage connected to said first valve chambn-the pressure passage being connected to the other diaphragm chamber the first valve being movable to connect its control passage with either the exhaust passage or with the pressure passage, yieldable means "urging the first valve to connect the control passage with the pressure passage, the exhaust passage leading to the second valve chamber, and means to move the second valve to cut off said exhaust passage, there being no set sequence of operations for the two valves.

2. In a gas valve, a main "housing having an inlet and an outlet, and a valve seat between them, a valve-member cooperable with the valve seat, a diaphragm for operating the valve, said diaphragm extending across the housing to provide a first diaphragm chamber, a cap member adapted to "fit over the housing and having edges to clamp the diaphragm to the housing, and providing 'a second diaphragm chamber, a valve housing member having two valve chambers therein, a valve in each valve'chamber, a con- 12 trol passage from one diaphragm chamber to the :flrst-valve chamber, an exhaust passa esan'd a pressure passage :connected to said .first valve chamber, the pressure-passage oi the first valve chamber being connected directly to the other diaphragm chamber, the first valve being movable to connect its control passage with either the exhaust passage orwith thepressure, passage, the exhaust passage leading to the second valve chamber, an exhaust passage and a-pressure-passage connecting into the second valve -zchambter, said pressure passage of the second valve'chamber being connected directly to the other diaphragm chamber, the second valve being movable to cut off either of them, whereby to-connectthe exhaust passage of the'first valve chamber'either to't-he exhaustpa'ssageor' to thepressure passage of the second valve chamben'and yieldable'means :urging the second valve'to connect the exhaust passage from "the first valve chamber with the "exhaust passage of the second valve chamber.

3. In a gasval-ve, acontrolf valve housing comprising a base having two :cylindrical members upstanding therefrom, a pressure passage in the base leading into the-centralparts of bothcylindrical members, a connecting'passage in the base leading from the first cylindrical member to'the second cylindrical member, an exhaust passage leading from; the second cylindrical 'member, valvemeans in each cylindrical member, each valve means comprising-a valve chamber, a pair of valve seats and avalve member movable in the chamber between the 'valve seats, thepressure passage being connected toz'one valve aseatof eachz'chamber, the 'connectinggpassage being connected from the other seat of the first valve means to thesecond'valve "chamber, the exhaust passage being connected to the other :seat :of the second valve .means, and means 'jyieldably biasingthe second valve'member toclose off-the exhaust passage.

4. In a gas valve, a diaphragm valve :mechanism for controlling gas flow from 'an inlet -to an outlet,-a first and a second diaphragm chamber onopposite sides of thediaphragm, a'control valve housing comprising a base having two cylindrical'members upstanding therefrom, a pressure passage in the base leading into-the central parts of both cylindrical members, a *connectingpassage in the base leading from thefirst cylindrical member to the second cylindrical member, an exhaust passage leading from the second cylindrical member, a control passage leading into the first cylindrical member, valve means in each cylindrical member, each valve means comprising a valvechamber, :a pair of valve seats and a valve member *movable in the chamber between the valve seats, the .0011- trol'passage being connected into the first diaphragm chamber, the pressure passage being connected to'one valve seat of each chamber, the connecting passage being connected from the other seat of the first valve means to thesecond valve chamber, the exhaust passage being connected to the other seat of the second valve means, the pressure passage being \connected with the inlet side of :the diaphragm valve, the control passage being connected with one dia phragm chamber, means yieldably biasing the second valve .member to close off the exhaust passage, and means yieldably biasing the first valve member to close off the connecting passage.

5. In a gas valve, a diaphragm valve .mechanism .for controlling gas flow from aninletto an 13' outlet, a first and a second diaphragm chamber on opposite sides of the diaphragm, a control valve housing comprising a base having two cylindrical members, a pressure passage leading into the central parts of both cylindrical members, a connecting passage leading from the first cylindrical member to the second cylindrical member, a control passage leading into the first cylindrical member, valve means in each cylindrical member, each valve means comprising a valve chamber, a pair of valve seats and a valve member movable in the chamber between the valve seats, the control passage being connected into the first diaphragm chamber, the pressure passage being connected to one valve seat of each chamber, the connecting passage being connected from the other seat of the first valve means to the second valve chamber, an exhaust passage connected to the other seat of the second valve means, the pressure passage being connected with the inlet side of the diaphragm valve, the control passage being connected with one diaphragm chamber, means yieldably biasing the second Valve member to close off the exhaust passage, means yieldably biasing the first valve member to close oil the connecting passage, means to shift the first valve in response to predetermined conditions, from closing the connecting passage to closing the pressure passage,

whereby the one diaphragm chamber may a change from pressure to exhaust and the diaphragm valve may open, and means to shift the second valve from closing its pressure passage to closing its exhaust passage, whereby the diaphragm valve may be reclosed.

6. In a gas valve, a diaphragm valve mechanism for controlling gas fiow from an inlet to an outlet, a first and a second diaphragm chamber on opposite sides of the diaphragm, a control valve housing comprising a base having two cylindrical members, a pressure passage leading into the central parts of both cylindrical members, a connecting passage leading from the first cylindrical member to the second cylindrical member, a control passage leading into the first cylindrical member, valve means in each cylindrical member, each valve means comprising a valve chamber, a pair of valve seats and a valve member movable in the chamber between the valve seats, the control passage being connected into the first valve chamber, the pressure passage being connected to one valve seat of each chamber, the connecting passage being connected from the other seat of the first valve means to the second valve chamber, an exhaust passage connected to the other seat of the second valve means, the pressure passage being connected with the inlet side of the diaphragm valve, the control passage being connected with one diaphragm chamber, means to shift the first valve in response to predetermined conditions, from closing the connecting passage to closing the pressure passage, whereby the one diaphragm chamber may change from pressure to exhaust and the diaphragm valve may open, and means to shift the second valve from closing its pressure passage to closing its exhaust passage, whereby the diaphragm valve may be reclosed, said means to shift the first valve comprising a valve stem, a coil, a movable armature, an operating member responsive to the movement of the armature to actuate the valve stem, manual means to actuate the valve stem when the coil is inoperative including a first member movable from a released position to an actuating position adjacent the armature, a second member engageable with the operating member to move the same and actuate the valve stem, means connecting the first and second members so that when the first member is moved to its actuating position the second member will be moved to actuate the valve stem, and means releasably holding the manual means in actuated position whereby when the coil is energized the first member is returned to its released position and the second member is released.

'7. In a gas valve, a main housing having an inlet and an outlet, a valve seat between the inlet and the outlet, a valve member cooperable with the valve seat, a diaphragm for operating the valve extending across the housing to provide a first diaphragm chamber, a cap-like member adapted to fitover the housing to provide a second diaphragm chamber, a valve housing member having first and second valve chambers therein, a valve in each valve chamber, a' control passage from one diaphragm chamber to the first valve chamber, an exhaust passage and a pressure passage connected to the first valve chamber, the exhaust passage leading to the second valve chamber, the valve in the first valve chamber being movable to connect its control passage with either its exhaust passage or its pressure passage, yieldable means urging the valve in the first valve chamber to connect the control passage with the pressure passage, an exhaust passage and a pressure passage connected into the second valve chamber, said pressure passage being connected directly to the other diaphragm chamber, the valve in the second chamber being movable to connect the exhaust passage from the first valve chamber with either the exhaust passage or the pressure passage of the second valve chamber, and yieldable means urging the valve in the second valve chamber to connect the exhaust passage from the first valve chamber with the exhaust passage of the second valve chamber.

8. In a gas valve for use with a heater for conditioning the media within an enclosure,.a main housing having an inlet and an outlet, a valve seat between the inlet and the outlet, a valve member cooperable with the valve'seat, a diaphragm for operating the valve extending across the housing to provide a first diaphragm chamber, a cap-like member adapted to fit over the housing to provide a second diaphragm chamber, a valve housing member having first and second valve chambers therein, avalve in each valve chamber, a control passage from one diaphragm chamber to the first valve chamber, an exhaust passage and a pressure passage connected to the first valve chamber, the exhaust passage leading to the second valve chamber and the pressure passage leading directly to the other diaphragm chamber, the valve in the firstvalve chamber being movable to connect the control passage with either its exhaust passage or its pressure passage, means responsive to the temperature of the media within an enclosure for actuating the valve in the first valve chamber, an exhaust passage and a pressure passage connected into the second valve chamber, the valve in the second chamber being movable to connect the exhaust passage from the first valve chamber with either the exhaust passage or the pressure passage of the second valve chamber, and means responsive to the temperature in the heater for actuating the valve in the second valve chamber.

9.1n a gas valve for use with a heater for conditioning the media within an enclosure, a

main housing having an inlet and an outlet, -a

valve seat between the inlet and the outlet, a valve member cooperable with the valve seat, a

diaphragm foroperating the valve extending chamber, a valve housing member having first and second valve chambers therein, a valve in each valve chamber, a control passage from one diaphragm'chamber to'the first valve chamber,

an exhaust passage and a pressure passage connected to the first valve chamber, the exhaust passage leading to the second valve chamber and 'the'pressure passage leading directly to the other diaphragm chamber, the valve in the first valve chamber being movable to connect its control .passage with either its exhaust passage or its pressure passage, yieldable means urging the valve in the first valve chamber to connect the control passage with the pressure passage, means responsive to the temperature of the media Within an enclosure for actuating the valve in the first'valve chamber, an exhaust passage and a pressure passage connected into the second valve chamber, the valve in the second chamber being movable to connect the exhaust passage from the first valve chamber with either the exhaust passage or the pressure passage of the second valve chamber, yieldable means urging the valve in thesecond valve chamber to connect the exhaust passage from the first valve chamber with the exhaust passage of the second valve chamber, andmeans responsive to the temperature in the heater for actuating the valve'in the second valve chamber.

10. In a gas valve for use with a heater for conditioning the media within an enclosure, a

main housing having an inlet and an outlet, a valve seat between the inlet and the outlet, a valve member cooperable with the valve seat, a diaphragm for operating the valve extending across the housing to provide a first diaphragm chamber, a cap-like member adapted to fit over -the housing to provide a second diaphragm chamber, 'a valve housing member having first and second valve chambers therein, a valve in each valve chamber, a control passage from one diaphragm chamber to the first valve chamber, an exhaust passage and a pressure passage connected to thefirst valve chamber, the exhaust passage leading to the second valve chamber, the

valvein the first valve chamber being movable to connect the control passage with either its exhaust passage or its pressure passage, means responsive'to the temperature of the media within'an enclosure for actuating the valve in the 16 first valve chamber, an exhaust passage and a pressure passage connected into the second valve chamber, the valve in the second chamber being movable to connect the exhaust passage from the first valve chamber with either the exhaust passage or the pressure passage of the second valve chamber, and means responsive to the temperature in the heater for actuating the valve in the second valve chamber, said last named actuating means comprising a support, power means oppositely movable, abutment means moved by the power means, a first lever pivoted onto the support and engageable by the abutment means, a second lever pivoted on the support, the levers overlapping and extending in opposite directions from their pivots, a spring connecting the levers, it being connected to the second lever on one side of the pivot of the first lever, and connected to the first lever on the same side of its pivot, the first lever being movable to displace said last connection from one side to the other of the pivot of thesecond lever, whereby the first lever is always urged in one direction by the spring, and the other lever is moved with a snap action upon movement of the first lever, andan adjustable connection between the second lever and'the valve'stem to provide a differential between the position of the power means for shifting the valve in one direction and the position for shifting it in the other.

CLAUDE M. GARNER.

REFERENCES "CI-TED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 937,678 Glauber Oct. .19, 1909 961,821 Walker June 21, 1910 1,722,920 I-Iynes July 30, 1929 2,031,932 Cornell Feb. 25, 1936 2,051,294 Gauger Aug. .18, 1936 2,051,295 Gauger Aug. 18, 1936 2,112,397 Gauger Max: 29, 1938 2,123,814 Summers July 12, 1938 2,138,503 OBrien Nov. 29, 1938 2,161,248 'Denison June 6, 1939 2,218,861 Stumpf Oct. 22, 1940 2,220,479 DeBell Nov. 5, 1940v 2,222,141 DenisOn NOV. 19, 1940 2,232,502 Wittmann Feb. 18, 1941 2,244,555 Harris June 3, 1941- 233171539 Ray Apr. 27, 1943 2,377,517 Ray. June 5, 1945 2,381,799 Berkholder Augp7, 1945 2,387,164 McCarty Oct. 16, 1945 2,407,761 McPherson Sept. 17, 1946 

